Method of and apparatus for forming concrete structures



May 6 LAKE METHOD OF AND APPARATUSFOR FORMING CONCRETE STRUCTURES A TT'oRNE Y.

May 6 1924. y

s.LAKE

METHOD yOF AND APPARATUS FOR FORMING CONCRETE STRUCTURES Filed MaI-ch 1. LSZ 3 Sheets-Sheet 2 IN V EN TOR.

A TTORNE Y.

May s 1924.

S. LAKE METHOD OF AND APPARATUS FOR FORMING CONCRETE STRUCTURES 5 Sheets-Sheet 5 Filed Marc IN! ENTOR.

ATTORNEY.

Patented May 6, 1924.

UNITED STATES SIMON LAKE, OF MILFORD, CONNECTICUT.

IIETEOD 0F AND APPAB'ATUS 4FOR FORMING CONCRETE STRUCTURES.

Application filed March 1, 1921.

To all lwhom it 'may concern.'

Be it known that I, SIMON LAKE, a citizen of the United States, residing at Milford, in the county of New Haven and State of Connecticut, have invented a certain new and useful Improvement in Methods of and Apparatus for Forming Concrete Structures,of which the following is a full, clear, and exact descri tion.-

It is well nown to those familiar with the art of working concrete that to secure a perfect bond between the various parts of a concrete structure it is important to have the concrete applied to the forms or molds continuously, otherwise im erfect union of the parts will result and t e structure will be materially weakened. Also, pressure has been found to increase the density and strength of concrete if applied while the mixture is plastic and before it has begun to set. y

It has been found advantageous, especially where metal reinforcing members are use to hasten the drying of the concrete by artiicial means so as to prevent rusting of the reinforcing members and subsequent weak- 'ening of their bond with the surrounding concrete. This protection of the reinforcing members, and also of the concrete itself is enhanced by the application of water roofing material to the structure while stil plastic and referably simultaneously with the ap lication of artificial heat.

he object of my invention is to provide a method of and apparatus for forming concrete structures or bodies whereby the concrete may be molded under pressure and all excess air and moisture expressed therefrom and removed and the body subsequently and while still in a plastic state subjected to the action of articial heat and, if desired, the action of a waterproofing and pore-filling agent.

The invention consists in a method of and apparatus for forming concrete bodies comprisin the mixing of the concrete, extraction o air therefrom, forcing the thus densified and homogenized mixture into a mold by pressure, extraction of excess water from the concrete while in the mold by the continued application of pressure and suction and subsequent heating and drying of the thus-formed concrete body in the mold; the concrete mixture being once freed `from trapped air being subsequently so handled as to preclude the possibility of air being again Serial No. 448,838.

trapped in it While it is undergoing molding, all as I will proceed now to explain and finally claim.

h In the accompanyin drawin illustrating the invention in t e severa ii res of which like parts are similarly designated, F1 ure 1 is a sectional elevation showing an em odiment of my a paratus whereby my method may be carrie out. Fig. 2 is a fragmentary longitudinal sectional view showmg one end of my mold with its core and connections. Fi 3 is a transverse section through the mol alone taken in the plane of imc 3 3, Fig. 2. Fig. 4C is an elevational lview of the core otra reduced scale. Fig. 5 1s an enlarged transverse section of the core of Fig. 4. Fig. 6 is a view similar to Fig. 5 but showing a modification in which the coro is constructed wholly of metal. Fig. 7 is a central longitudinal section of a telegraph pole such as may be produced by my method and apparatus. Fig. 8 is an enlarged fragmentary detail view showing the method of reinforcing the pole of Fig. 7. Fig. 9 is a section taken on line 9-9 of Fig. 8. Fig. l() is a view showing the mode of assembling the main reinforcing members.

Referring particularly to Fig. 1, the apparatus comprises a concrete mixer 1, mounted upon andsupport'ed by a tank 2, hereinafter called the pressure tank. Extendingthrough the tank 2 and into the mixer 1 is a shaft 3 driven by suitable gearing 4 and carrying two stirrers, one of which 5 is located in the mixer and the other 6 in the pressure tank. Communication between the mixer and pressure tank is afforded by means of a tube 7 controlled by means of a gate valve 8. Snitable hoppers or chutes 9, 10 and 11 may be provided above the mixer 1 for the purpose of feeding cement, sand and gravel thereto. The mold of my apparatus (see Figs. 1, 2 and f3 comprises four sections 12, adapted to be olted together upon spacer pieces 13 whereby channels 14 are formed extending longitudinally of the mold and providing means whereby easy How of the concrete ma be attained. The bottom spacer piece13 1s pipe-tapped and rovided with a pipe 15 which 1s connecte through a cleaning trap 16 (Fig. 1) with a tube 17 communicatin with the bottom of the ressure tank an controlled by a gate va ve 18. The top spacer piece 13 Fig. 2) is provided with a longitudinal groove 19 an faced with a strip of filtering material 20, such as will allow water and air to pass through it but will not allow the passage of other ingredients of the concrete. This s acer piece 1s also pipetapped and provide with a pipe 21 communicating with the groove 19 and with the exhaustion side of a compression-exhaustion pump 22 (Fig. 1) through pipes 23 and .24, setthng tank 25 and pipe 26. The settllng tank 25 is provided with a sight glass 2 having a drain cock, for a purpose later aplpeering. The ends of the mold are closed by eads 29 having bearing members 30 in which are supported trunnions 31 arranged in the ends of a core 32 and serving to support the core axially of the mold.

The core 32 may be constructed in a variety of ways so long as provision is made for heating it internally. I have shown in Figs. 2, 4, 5 and 6, two forms of core adapted to the purpose of my invention. In Figs. 2, 4 and 5 the core is shown as comprising a centrol member 33, preferably of wood, and provided with a plurality of longitudinal grooves 34, the whole being covered with a metallic sheath 35 which in addition to formin a casing therefor provides spaces 36 at t e ends thereof communicatin with the grooves 34, and into these spaces ead steam inlet and drain pipes 37 and 38, respectively, whereby steam may be circulated through the grooves 34, and the core thereby heated. In Fig. 6 the core is shown as made entirely of metal, and comprises an inner tubular member 39 and an outer tubular member 40 forming be tween them an annular steam space 41.

Again referring to Fig. 1, it will be seen that the `pump 22 is, in addition to its connection with the mold, connected also with the pressure tank 2 through a pipe 42 provided with a two-way valve 43 which communicates also with a compressed air reservoir 44 by means of pipe 45. This reservoir 44 receives its compressed air through pipe 46 from the compression side of pump -22. Communication between the mold and pump 22 is controlled by a valve 47, and an automatic air inlet valve 48 is provided so that air may be supplied to the pum after all air has lbeen exhausted by it m the mold.

Referring now to Figs. 7 to 10 inclusive, wherein a concrete telegraph pole, such as may be constructed by my method and apparatus is shown, a reinforcin framework is provided composed of longitudinal rods 49 surrounded at intervals throughout their length by rings 50 to which they are welded or otherwise tied. Around the framework thus constructed wires 51 ma be spirall wound to form a sort of ba et-work. Iyf desired, wire cloth or coarse wire mesh may be substituted for the wires 51.

It will be observed by reference particularly to Figs. 8 and 9 that the channels 14 of the mold lform ribs 52 on the side of the pole, and in these ribs I prefer to form sockets 53 to provide means whereby a lineman may climb the pole by inserting his climbing spurs therein. 1f desired, a cap 54 may be inserted in the top of the pole to exclude water from the interior thereof.

The method is carried out as follows First the core 32 is covered with some fusible material, such as paraffin. I prefer the use of paraffin for the reason that it is not sticky and leaves the core clean when removed therefrom by heat. Then a strip of ordinary tar or building paper 55 (Fig. 5) is wrapped com letely around the core throughout its lengt and this covering of paper is coated with a generous application of tar or pitch or the `like fusible waterproofing material. The core is then slipped inside of the reinforcing basket and by means of its trunnions 31 supported in the bearing members 30 of the heads 29 of the mold. The mold is then com letely assembled around the core and reinibrcement, suitable packing material or gaskets being interposed, if necessary, between the sections 12 and spacers 13 to form an airtight chamber of the mold. The mold is supported in operative relation to the casting apparatus upon stanchions 56, and the various pipes are connected with it. The

-valve 8 being closed, a charge of concrete ,ingredients is run into the mixer 1 from. vthe hoppers 9, 10 and 11 and .water added thereto and the shaft 3 rotated to operate the stirrers 5 and 6. Also the pum 22 is put in operation and the valve 43 justed so as to establish communication between the exhaustion side of the pump and tank 2, valve 47 being meantime closed, whereb the pump will exhaust the air ,from t 2 and will furnish compressed air Vto reservoir 44.

After the concrete has been suiciently mixed by mixer 1 the valve 8 will be opened and the concrete will be sucked into tank 2 'by reason of the vacuum therein fproduced =by the pump 22, and when su cient concrete is run into tank 2 to charge -the mold, the gate valve 8 is again closed 'and the suction continued during agitation of the concrete by strrer 6 untl al of the trapped air has been removed. Now, the valve 43 is adjusted so as 4to cut off suction from tank 2 and valve'47 is opened to create a vacuum in the mold. As soon as the air has been withdrawn from the mold, the mixing is stopped and valve 43 is adjusted to admit com ressed air from reservoir 44 to tank 2 an is oppned, wherebI the concrete is forced, by t e pressure o the air, into the mold. As all air has been extracted from tube 17 and from the mold, it will be apparent gate valve 18" lll that no air can come in contact with the concrete. The vacuum pump 22 is kept running, and when the mold is filled, the great pressure caused yby the air in tank 2 will cause any excess moisture in the concrete to be expressed through the filter material 20, and this water will be sucked out through pipe 21 and deposited in settling tank 25, from which it may be withdrawn throuvh the drain cock of lass 27 as required. The operation of tie pump `22 is now stopped, and the concrete body in the mold allowed to get its initial set. Then the top of the mold is removed and the body exposed, and to hasten its hardening steam is allowed to circulate through the core through pipes 37 and 38.

I have found that concrete castings may be rapidly dried out without causing cracks in the casting if the heat is applied gradually to the interior of the mass so as to give a gradually increasing temperature until the entire mass becomes dry, at which time it has attained a considerable degree of hardness and tensile strength and has also be-` come thoroughly bonded to its reinforcement.

The heating of the core causes its paraffin coating to fuse and admits of the subsequent withdrawal of the core with comparative ease.

On the casting becoming dry it is lifted from its mold and while still warm a coating of any suitable waterproofing or enameling compound may be applied to it. At this time the pores of the concrete adjacent to the surface are still open, due to its expansion under heat, and the waterproofing material therefore enetrates into these pores, and when shrinkage takes place the surface is both waterproof and air-proof, and if a non-conducting waterproofing material is used, it also makes an excellent non-conductor of electric currents. Heating up of the core has also caused the fusible compound surrounding the core to penetrate the interior surfaces of the body with a waterproofing compound, so that if sweating should occur on the interior of the casting, it cannot penetrate to the metal reinforcement, thus insuring long life to the structure.

While I have described my method and apparatus as adapted to the manufacture of a :concrete telegraph ole, it is to be understood that it is equallly well adapted to the manufacture of various other concrete structures. Furthermore, it is conceivable that various changes may be made in the method and apparatus without departing from the spirit ofthe invention or the scope of the following claims.

What I claim is 1. A method of forming concrete bodies, which consists in forming a mold, exhausting the air therefrom, forcing conci-steunder pressure into said mold, continuing such pressure after the mold is filled to express the surplus moisture from said concrete, withdrawing such surplus moisture from said mold, and applying heat to the concrete body to hasten its drying.

2. A method of forming hollow reinforced concrete bodies, which consists in forming a mold, supporting a core in said mold, exhausting the air from said mold, forcing concrete under pressure into the space within said mold surrounding said core, extracting the surplus moisture from said concrete and withdrawing such moisture from the mold, and applyln, heat to the interior of said concrete body 1n the mold by a heating Huid introduced through the medium of said core.

3. In an ap aratus for forming concrete bodies, a mol a concrete mixer provided with a concrete receiving pressure tank connected with said mold, means connected with said mold for withdrawing the air therefrom, and means for establishing pressure in said ressure tank to force the concrete there rom and into said mold, the means for withdrawing air from the mold being thereafter actuated to withdraw excess moisture frolii the pressure-introduced concrete in the mo 4. In an apparatus for forming concretew bodies, a mold, a concrete mixer, a pressure tank adapted to receive concrete from said mixer, connections between said tankl and mold, a reservoir for the storage of air under pressure, a compression-exhaustion apparatus, connections between said compressionexhaustion apparatus and said tank reservoir and mold, and valves for controlling the operation of said compression-exhaustion apparatus relative to said tank reservoir and mold for the purpose specified.

5. In an a aratus for forming concrete bodies, a mol, a concrete mixer, a com ression-exhaustion pump, a pressure tank aving valved connection with said concrete mixer, mold and pump, a storage reservoir adapted to receive and store air under pressure from said pump and connected with said pressure tank, an air intake conduit for said pump communicating with said mold, and a settling tank interposed in said conduit, whereby concrete may be forced under ressure into said mold, from which the air has been exhausted, and therein subjected to pressure to express surplus moisture and this moisture withdrawn and deposited in the settling tank as specified.

In testimony whereof I have hereunto set my hand this 28th day of February A. D.

SIMON LAKE. Witnesses GERTRUDL M. LYNCH, R. M. Kun.

`sus 

